1. Field of the Invention
The present invention relates generally to animated scenes, and more particularly to a system and method for encoding a scene graph.
2. Related Art
The Internet is rapidly becoming a staple medium for today's business and industry. Businesses of all types and sizes rely on the Internet as a tool for promoting their business and for making their business better known to the public. Businesses that rely on the Internet use it as a medium for providing the general public with information about their company and the products and services they offer. Many businesses even sell their products over the Internet.
The Internet, however, is not restricted to use by businesses. In fact, governmental organizations, clubs, special interest groups, other organizations and even individuals are among the many diverse parties who rely on the Internet to help disseminate information about their organization or about themselves.
As more and more parties have posted web pages, competition among them has grown. In the early stages of its evolution, the "high-tech" Internet web page included text accompanied by still photos. However, as advertisers have upped the ante to capture the users' attention, web pages have evolved dramatically. To make their sites more appealing to users, contemporary Internet sites include animated multi-color graphics and accompanying video and sound tracks.
However, in Internet applications as well as other environments, animated graphics and associated video and sound tracks do not come without a price. These enhanced features are typically resource-intensive. That is, they usually require a relatively significant resource pool to operate quickly and effectively. One such resource is communications bandwidth, and another is processing power. Providing an animated graphics scene to a user's web browser requires a fair amount of bandwidth. As the complexity of the animations increases, the size of the files required to provide the animation to the user tends to increase as well. Consequently, the time required to download such animations to a user's computer increases. Although communication speeds across the Internet and into a user's home or office are increasing, the communications technology typically cannot keep up with the demands of contemporary animations. Furthermore, not every user has the latest and fastest communications interface available to them. Thus, the resolution, complexity and speed of an animation provided with a web page are often limited by the bandwidth of the communications interfaces.
Additionally, animations are computed and rendered by the user's computer. As such, the programmer cannot be assured of a particular level of processing power to create and display the animation. In fact, while some users have the latest and fastest machines to browse the web, others are still using machines which are one or more generations old, and which therefore do not have the processing power to quickly render animated scenes.
Some conventional techniques are utilized for optimizing the creation and rendering of animated scenes. One conventional technique, referred to as PHIGS, provides some optimization in that it allows the creation and reuse of objects through scene graphs. VRML is another technique which utilizes a scene graph for generating animated scenes. At the highest level of abstraction, VRML is a way for objects to read and write themselves. The Inventor.RTM. product available from Silicon Graphics, Inc., of Mountain View, Calif., is a predecessor to VRML. However, even with PHIGS and VRML, there are inherent inefficiencies which can slow down the delivery or rendering of an animated scene. The designers of Inventor.RTM., VRML and PHIGS required a relatively large engine to implement and execute scenes.